Network Mobility (NEMO)
▀ NEMO Overview
▄ Cisco ASR 5x00 Packet Data Network Gateway Administration Guide
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NEMO4G-HA removes from the associated Enterprise VRF routing table any prefixes that are
not included in a scheduled or ad-hoc NEMO MIPv4 re-registration request from a given MR
(assuming these were present in a previous NEMO MIPv4 RRQ). E-PGW shall update the
external VRF router of the removal of such prefixes on the next eBGP update.
NEMO4G-HA accepts and installs any new prefixes that are included in a scheduled or ad-hoc
NEMO MIPv4 re-registration request to the associated Enterprise VRF routing table, as long
as it doesn't exceed the maximum number of supported prefixes per MR (up to eight). E-
PGW shall update the external VRF router of the newly installed prefixes on the next eBGP
update. NEMO4G-HA shall accept NEMO MIPv4 RRQs that do not include any prefixes in
the first initial RRQ and it shall accept prefixes advertised in subsequent RRQs.
In case of a prefix whose IP address or mask is changed on the MR, the MR will remove the
old IP address/mask and add the new IP address/mask prefix in a scheduled or ad-hoc NEMO
MIPv4 re-registration request and NEMO4G-HA shall remove the old route and add the new
route corresponding to the new prefix to the Enterprise VRF routing table
Overlapping IP addressing
NEMO4G-HA supports private and overlapping IP addressing across multiple Enterprises for the WAN IP
pools, MR-HADDR, and LAN prefixes.
NEMO MR Authorization
NEMO4G-HA authorizes a NEMO MIPv4 session only if a NEMO permission has been assigned to the underlying
PDN connection. NEMO permission should be assigned to the underlying PDN connection via either local
configuration (APN parameter) or based on a NEMO permission AVP assigned by the 3GPP AAA during the PDN
authorization. For local configuration, a new APN parameter is supported to enable NEMO permission at the APN/PDN
level within the P-GW service.
MIPv4 NEMO Protocol
NEMO4G-HA processes a Mobile IPv4 NEMO Registration Request (RRQ) received from the MR NEMO client.
NEMO4G-HA processes the first of three Cisco-specific MIPv4 Extensions of type Normal Vendor/Org Specific
Extension (NVSE) that are included in the MIPv4 NEMO RRQ. The three Cisco-specific NVSEs are placed after the
MIPv4 “Identification” field and before the mandatory MIPv4 “Mobile-Home-Authentication-Extension.” NEMO4G-
HA accepts the LAN prefixes (up to eight) encoded in the first Cisco-specific NVSE (vendor-type = 9). NEMO4G-HA
is not expected to process the other two Cisco-specific NVSEs with vendor-type = 49, which carry the Internal Interface
ID of the MR's Roaming Interface and the MR's Roaming Interface Bandwidth in Kbps, respectively.
Cisco-specific NVSEs follow RFC 3025 “Mobile IP Vendor/Organization Specific Extensions.”
GRE Encapsulation
User traffic shall be encapsulated over a GRE tunnel between the MR NEMO client and NEMO4G-HA. The IP
endpoints of the GRE tunnel shall be the IPv4 assigned to the MR modem during the Enterprise PDN connection setup
and the IPv4 address of the NEMO4G-HA service on the E-PGW.
NEMO4G-HA shall remove the GRE encapsulation before it forwards the outbound traffic towards the Enterprise VPN
via the associated SGi VLAN interface. Inbound traffic received through the same SGi VLAN interface shall be
encapsulated into a GRE tunnel before it's passed to the E-PGW service for forwarding to the MR through the proper
GTP/PMIP tunnel.
